The vertebrate kidney helps to keep the acidity of the body fluids constant by varying the amount of hydrogen ions (H+) it secretes into the urine. You can confidently predict that this aspect of kidney function will be controlled by ______.

Homeostasis ______.

Which of the following is a physiological response that takes place in many animals when they get too hot?

If your body is dehydrated, having insufficient fluid levels in the blood, the control center in the brain will stimulate the release of a hormone which will cause water to be reabsorbed into the blood during urine formation. When the control center senses that enough water is reabsorbed, it will stop the release of the hormone. This is an example of

Both a coronary bypass operation and a stent insertion procedure are treatments used for which of the following conditions?

Which of these carry(ies) oxygen-poor blood?

Blood pressure is lowest in ______.

You increase your risk of cardiovascular disease by reducing your consumption of ______.

White blood cells play a particularly important role in ______.

When you examine fluid that you have drawn from a blood vessel, you find that it is relatively high in carbon dioxide and waste products. Assuming that the fluid comes from a healthy individual, you conclude that the blood vessel from which you have drawn blood could have been ______.

The basic rhythm of the heartbeat is set by the ______.

Why does the left ventricle have a thicker wall than the right ventricle?

Why do diseases involving widespread infection usually result in a fever?

The transfer of antibodies from breast milk to an infant is an example of ______ immunity.

A new flu vaccine is needed every year because ______.

A substance that can elicit an immune response is called a(n) ______.

Which of the following cell types are the main warriors of cell-mediated immunity?

Where in a woman's reproductive tract does fertilization most often take place?

What moves the human egg through the oviduct?

A birth control pill works by

Menstruation ______.

Homeostasis maintains various levels within a narrow range only if environmental conditions do not fluctuate much.

The relaxing phase of the heart cycle is called systole.

In our hearts the left and right atria contract at the same time.

Antibody-mediated immunity involves the action of T lymphocytes.

The use of a male or female condom during sexual activity reduces the risk of the transmission of sexually transmitted diseases.